Polyhedral haloboranes as developer adjuvants with a polyethylene oxide condensation product

ABSTRACT

This invention relates to photographic films and developers and to improvement in film speed and top density which occurs by adding certain novel polyhedral haloborane compounds in synergistic combination with polyethylene oxide condenstaion products to the film-developer system. This invention also relates to improved developer tray life resulting from the use of these novel polyhedral haloboranes.

United States Patent [191 Bigelow *Jan. 15, 1974 [54] POLYHEDRAL HALOBORANES AS 2,843,484 7/1958 Baxendale 96/66 DEVELOPER ADJUV ANTS WITH A 2,739,894 3/1956 Rasch et a1. 96/66 2,913,339 1l/1959 Sottysiak et a]. 96/1 10 POLYETHYLENE OXIDE CONDENSATION 3,300,278 l/l967 Nies et a] 423/280 PRODUCT Inventor: John H. Bigelow, Rochester, NY.

E. I. du Pont de Nemours and Assigneei Company, Wilmington, Del.

Notice: The portion of the term of this patent subsequent to Dec. 18, 1990, has been disclaimed.

Filed: Mar. 27, 1972 Appl. No.: 238,480

References Cited UNITED STATES PATENTS 1/1971 Bard 96/66 Primary ExaminerJ. Travis Brown Assistant Examiner-John L. Goodrow Att0meyWilliam R. Moser [5 7] ABSTRACT This invention relates to photographic films and developers and to improvement in film speed and top density which occurs by adding certain novel polyhedral haloborane compounds in synergistic combination with polyethylene oxide condenstaion products to the film-developer system. This invention also relates to improved developer tray life resulting from the use of these novel polyhedral haloboranes.

21 Claims, No Drawings POLYHEDRAL HALOBORANES AS DEVELOPER ADJUVANTS WITH A POLYETHYLENE OXIDE CONDENSATION PRODUCT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to chemically sensitized, photographic silver halide emulsions and to a light sensitive coated layer prepared from said emulsion and to the processing or developing solutions used for producing or developing the image placed on said layer. This invention also relates to the addition of certain polyhedral haloboranes to said emulsion or said developer and to the synergistic effects obtained when these haloboranes are added in conjunction with polyethylene oxide condensation products. Another aspect of this invention relates to lithographic type photographic elements and developers to which these polyhedral haloboranes and polyethylene oxide condensation products have been added.

2. Description of the Prior Art Combinations of special emulsions and developers are needed to produce the high contrast, sharp toe, low fog and high top density characteristic of graphic arts products such as lithographic films. Developers commonly used to obtain this characteristic shape of the sensitometric curve, relating developed image density to log of the exposure, are based mainly on hydroquinone as taught by Mason in Photographic Processing Chemistry, the Focal Press (1966). These developers also contain sodium formaldehyde-bisulfite as taught by Yule in the Journal of the Franklin Institute, 239, (1945), p. 221 and others. After an induction period so called infectious development occurs giving rise to the sharp toe and steep gradient (or gamma) necessary to achieve good image quality required by this process. Various researchers have added certain adjuvants to achieve faster results or improve image quality. Blake (U.S. Pat. .No. 2,533,990, issued Dec. 12, 1950) has found that the addition of mannitan monolaurate polyoxyethylene ether containing 20 oxyethylene groups per molecule divided in 3 chains to hydroquinone-type developers resulted in a substantial improvement in film gradient at a slight decrease in film speed.

P. J. l-lillson has also reported in Photographic Science and Engineering, 13; (1969), p. 165 that development of photographic films in hydroquinone-type developers can be strongly retarded by the addition of polyethylene glycols and other related nonionic surfactants. Other uses of polyethylene oxide'compounds in emulsions and developers is well covered by Blake and Baldsiefen in U.S. Pat. No. 2,400,532, issued May 21, 1946 and by Blake et a]. in U.S. Pat. No. 2,423,549, is sued July 8, 1947 and again by Blake in U.S. Pat. No. 2,441,389, issued May 11, 1948. Bigelow has found (U.S. Pat. No. 3,637,392 issued Jan. 25, 1972) that certain boron hydrides are useful as chemical fogging agents in direct positive emulsions.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a novel developing system for use with common silver halide films. Another object is to provide a system which will give improved film speed, top density and the like. Still another object is to provide faster processing in lith-type" developers which use-hydroquinone or substitutions thereof as the main developing agent. Yet another object is to improve the activity of said developers and to increase the so-called tray'life" by reducing the pH at which the developing system may be used. Another object is to achieve the above objects without producing deleterious effects such as processing defects and artifacts. These and other objects are achieved by developing the photographic film in the presence of certain polyhedral haloborane compounds, containing l0 or 12 boron atoms in the framework of the molecule and in which 50 percent or more of the hydrogen atoms are replaced by halogen atoms, and synergistically in the presence of a polyethylene oxide condensation product.

DESCRIPTION OF THE PREFERRED EMBODIMENT In its preferred embodiment, this invention comprises photosensitive silver halides dispersed in suitable binders such as gelatin which may be modified with certain other binding agents such as polyethylacrylate. These emulsions may also be further sensitized by the addition of gold and sulfur and after sensitization, coating and wetting aids and other adjuvants such as hardeners may also be added. Polyethylene oxide condensation products are preferably added to the emulsion at this point, though they may be incorporated at any point during the emulsion making-preparation period. These polyethylene oxide condensation products are preferably added to the emulsion in the range of 0.0025 g to 2.0 g per 1.5 mole of silver halide. A particularly useful polyethylene oxide condensation product is octylphenoxypolyethoxy ethanol added dissolved in water/alcohol mixtures at a preferred range of 0.01 g to 1.3 g of the polyethylene oxide condensation product per 1.5 mole of silver halide. The emulsion is then coated on a suitable support such as polyethylene terephthalate and, after drying, overcoated with a thin stratum of gelatin which may be hardened to protect the emulsion during handling. These emulsions after exposure are then processed in a developer containing the polyhedral haloborane compounds of this invention. These polyhedral haloborane compounds are borane polyhedrons, or fragments thereof containing 10 or 12 boron atoms interconnected to each other and preferably containing halogen atoms in place of most of the hydrogen substituents normally associated with polyhedral boranes. The polyhedral haloboranes compounds are well described by Muetterties and Knoth in Polyhedral Boranes, Marcel Dekker, Inc., 1968. A preferred cornpound ISHHZBJ-ZCWIHW' 7H O which may be added to the developer in Em range of .005 g to 1.5 g per liter of developer and in the preferred range of 0.1 g ,to 0.5 g per liter of developer. When so processed in developers containing the polyhedral haloborane compound, emulsions having polyethylene oxide condensation products show a surprising and novel increase in speed and top density over the emulsions which do not contain the polyethylene oxide condensation product. When these polyhedral haloborane compounds are incorporated in common lith-type developers containing mainly hydroquinone as the sole developing agent, or substituted hydroquinones such as chloro, bromo or iodohydroquinone, or catechol or pyrogallol or others well known to those skilled in the art, the resulting film processed therein will, in comparison to films processed in lith-type developers without the polyhedral haloborane compounds of this invention, display some or all of the advantages of a shorter process time; higher speed; higher Dmax; longer developer tray life; the production of higher lith quality such as a shorter toe, more neutral color, improved dot" quality and longer halftone scale; lower developer sludge formation and resistance to aerial oxidation; and increased developer capacity.

The emulsions which may be used to practice this invention include all of the common silver halide types used, for example, in graphic arts, screened medical xray, industrial or nonscreened x-ray, negative cine or positive, color, etc. and may also include orthochromatic, panchromatic or infrared sensitizing dyes. These aqueous silver halides include, for example, silver chloride, bromide, chloro-bromide, bromo-iodide, chloro-iodide or mixtures of chloride-iodide-bromide and also litho combinations having a majority of chloride with the rest being bromide alone or bromide with a small amount (generally less than percent) of iodide useful in lithographic films. These silver halides may be dispersed in gelatin or any other organic, macromolecular water permeable colloid, part or all of which may be replaced by synthetic agents, e.g., partially hydrolyzed polyvinyl acetates, polyvinyl ethers and acetals containing a number of extralinear Cl-l CH OH groups. Other useful binders include hydrolyzed interpolymers of vinyl acetate and unsaturated addition polymerizable compounds such as maleic anhydride, acrylic and methacrylic acid, ethyl esters and styrene. Suitable colloids of the last mentioned type are disclosed in U.S. Patents 2,276,322; 2,276,323; and 2,347,81 1. Suitable mixed colloids are described in Assignees U.S. Pat. No. 3,142,568 and U.S. Pat. No. 3,203,804. These emulsions may be sensitized with gold and sulfur in a manner known to those skilled in the art. In addition they may include wetting agents, antifoggants, hardeners and other useful adjuvants.

The emulsions of this invention may be coated on any conventional photographic base or support such as glass, metal, various waterproof papers, cellulose derivatives, super polymers such as nylon, polyvinyl chloride, polystyrene. Preferentially, we coat on polyethylene terephthalate subbed and prepared as described by Alles, U.S. Pat. No. 2,779,684, Example IV.

After coating and drying the emulsion, the resulting film is preferably over-coated with a thin stratum of gelatin which may be hardened so as to protect the emulsion and improve the surface of the film. This over-coating, or alternatively the emulsion underneath or the substratum anchoring layer or the anti-curling backing layer, may also contain certain adjuvants which are useful in preventing static.

Polyhedral haloboranes which can be used in practising this invention include the following:

z io io cs B cl Br Z IO IO Many suitable polyethylene oxide condensation products may be used synergistically with the above polyhedral haloborane compounds of this invention to produce the novel results of this invention. Many of these are well described by Blake et al. in U.S. Pat. No. 2,400,532, 2,423,549 and 2,441,389. Other suitable polyethylene oxide condensation products include:

Octylphenoxypolyethoxy ethanols Ethylene oxide condensates Polyethylene oxide (20 moles)/mole cetylether Polyethylene oxide (20 moles)/mole oleylether Polyethylene oxide (40 moles)/mole stearate Polyethylene glycol condensates Polyoxyethylene stearates Polyoxyethylene oxide oleic alcohol Polyoxyethylene oxide tallow amine This invention will be illustrated by, though not limited to, the following examples.

EXAMPLE I A standard silver halide lithographic emulsion was prepared consisting of about mole percent of silver chloride and about 30 mole percent of silver bromide. This formulation is similar to that described by Nottorf in U.S. Pat. No. 3,142,568. The emulsion was dispersed in an aqueous gelatino-ethylacrylate binder and brought to its optimum sensitivity by the addition of gold and sulfur as well as being optically sensitized with an orthochromatic dye. The usual coating aids, antifoggants and hardeners were also added as well as the polyoxyethylene compound octylphenoxypolyethoxyethanol and which is added dissolved in a mixture of water and ethyl alcohol and is present in the emulsion at a level of about 1.5 grams of polyethylene oxide condensation product per 1.5 moles silver halide. After coating the emulsion on polyethylene terephthalate base, followed by drying, a thin overcoating of gelatin was applied. Strips from this coating were exposed for 20 seconds through a 2 sensitometric step wedge to a white light tungsten source followed by a 2 minute development at 68F in a developer of the following composition:

Water 500 cc Sodium Formaldehyde Bisulflte 42.5 g

NaOH 4.5 g KB! 1.8 g K CO 12.5 g

Experiment Amount of Polyhedral Relative Top Haloborane Added to Speed Demity Developer (g/liter) A Control None 5.51 B 0.005 109 Continued Experiment Amount of Polyhedral Relative Top Haloborane Added to Speed Density Developer (g/liter) C 0.010 120 D 0.050 178+ E 0.10 1060 6.35 F 0.20 1070 6.48 G 0.30 980 H 0.40 870 6.18 l 0.50 985 6.3l

4 A! Step No. 11 of the 2 step wedge The improvement in speed and top density is appar ent from this example. In addition above 0.01 g of polyhedral haloborane/liter of developer the toe portion of the H&D sensitometric curve is unusually shortened. Useful maximum levels appear to be about 0.20 g.

Additional wetting agents, sequestrants and adjuvants may be incorporated in this developer composition as known to those skilled in the art.

EXAMPLE II An iodobromide emulsion consisting of 1.67 mole percent silver iodide and 98.33 mole percent silver bromide was precipitated in an alkaline medium, dispersed in gelatin and then brought to its optimum sensitivity with gold and sulfur. After cooling the emulsion the usual wetting agents, buffers and hardeners were added and the emulsion split into two portions. One portion was kept as control and to the other was added 0.5 g

of a polyethylene glycol condensate, with an average molecular weight of 4000, per 1.5 mole of silver halide. Both portions were then coated on polyethylene terephthalate film and dried. Strips from these coatings were given second exposure on an Edgerton, Germeshausern and Greer (E.G.&G.) sensitometer through a fistep wedge followed by development in the developer of Example I at 80F for 2 minutes with the following results:

Step 11 on the V 2 step index The synergistic effect of the polyhedral haloboranes of this invention in combination with polyethylene oxide condensation product is clearly shown in this example.

EXAMPLE III The emulsion described in Example II was prepared and split into two portions. To one portion was added 0.8 g of I-I,B, CI,,'7I-I,O per 1.5 moles of silver halide prior to coating and the other coated without the polyhedral haloborane. A polyethylene glycol condensate with an average molecular weight of 4000 was added to each portion at a level of 0.2 g/l .5 mole silver halide. Strips from the coatings were given the same exposure as those of Example 1 followed by development in the same developer with and without the polyhedral haloborane and the following results obtained:

Sample Amount of Fog Rel. Top Gamma Polyhedral Speed Density l-Ialoborane added to Developer (g/liter) No None 0.05 3.ll 1.45 polyhedral haloborane Added to Emulsion Same as 0.2 0.05 187 3.21 1.90

above Polyhedral None 0.06 138 3.15 1.80 haloborane Added to Emulsion Same as 0.2 0.17 246 3.15 1.34

above At Step No. 11 of the 2 wcdge From the above one can see that when adding polyhedral haloborane to either the emulsion or to the developer one obtains a useful advantage of speed, gradient and Dmax over adding polyethylene oxide condensation product by itself, without any deleterious increase in fog. If one adds the polyhedral haloborane to both emulsion and developer one can obtain a substantial increase in photographic speed but at some in-' crease in fog and decrease in gamma.

EXAMPLE IV Sample strips of the coating prepared in Example I were given the same exposure and developed 2 minutes at 68F in the same developer composition of Example I except that various other polyhedral haloborane compounds were substituted at 0.2 g of compound/liter of developer as shown below. Results are also shown:

Polyhedral Haloborane Relative Speed Top Density Compound Tested None Control 100 4.4l l( 1 1: I550 6.3] l( :)4 lz io s s i270 6.2] l( 4 l: ie '1 1350 6.34 l( z)4 12 10 5 3 6.26 l io z s l090 6.23 a w i n 1530 6.3

At Step 1| EXAMPLE V hedral haloborane is considerably more stable and maintains an acceptable speed, contrast and density even after extensive use than the developer without the polyhedral haloborane. What is claimed is:

l. A process for developing photographic silver halide emulsions which comprises An emulsion similar to Example ll was prepared and split into five portions. In place of the polyethylene glycol condensate used in Example 11, the following polyethylene oxide condensation products were added:

Emulsion Polyethylene Oxide Condensation Product Used and a. t ti i th presence f a l h d l h l b Portion Amount (0.4g/l.5 mole AgX) rane and a polyethylene oxide condensation prod- A-l None Control 10 net, a silver halide emulsion with a developer, said A-2 None Control B 20 moles polyethylene oxide/mole cetyl ether polyhedral haloborane bemgaborane polyhedron, C 20 moles polyethylene oxide/mole oleyl ether or fragments thereof, containing 10 to 12 boron D Pmyelhyla"e meme atoms and in which at least a majority of the hydrogen substituents have been replaced with halogen atoms, and These samples were then coated and exposed per Exb. removing said emulsion from said developer. ample 11 followed by development in the developer of 2. The process of claim 1 wherein said developer Example 11 except that the developer used for portion contains, as the main developing agent, hydroquinone A-l had no polyhedral haloborane and that used for or a substituted hydroquinone.

A-2, B, C and D contained 0.2 g H B CI flI-I O per 3. The process of claim 2 in which said emulsion liter of developer with the following results: fo m a l r o a t,

Emulsion Portion Polyethylene Polyhedral Fog Relative Speed Gamma Top Density Oxide Haloborane in Condensation Developer Product in Emulsion A-l None None 0.21 100 1.50 3.30 A-2 None Yes 0.22 102 1.62 3.47 B Yes Yes 0.14 125 1.85 3.74 C Yes Yes 0.24 169 2.05 3.63 D Yes Yes 0.22 133 2.05 4.00-1- At Step No. l l of the \/2 wedge EXAMPLEVI V 4. The p rocess of claim 3'wherei n said polyhedral haloborane and said polyethylene oxide condensation product are present within said emulsion.

5. The process of claim 4 wherein there is about 0.0025 to 2.0 grams of polyethylene oxide condensation product per 1.5 mole of silver halide in said emul- In order to show improvement in developer stability, samples of the developer of Example 1 were prepared with and without the polyhedral haloborane H B CI '7H O at 0.2 g/liter of developer. These samples of developer were placed in an open 10 inch by 12 inch tray and aged 5 minutes. Sensitometric strips of 40 slonfilm from Example 1 were then exposed and developed The 9 of clalm 3 wherel" Said P y y in each of the two developers. Five square feet of this Oxide Condensation Product is Present within said fil hi h h d b full exposed, was then processed emulsion and said polyhedral haloborane is present through each of the developers followed by 2 more senwithin Said developersitometric strips. A second five square feet of fully ex- The pr of claim 6 wherein said emulsion posed film was then processed in a like manner foltains a ut 0.0025 to 21 grams f aid polyethylene lowed by two more sensitometric strips. in all, each deoxide condensation product per 1.5 moles of silver halveloping solution was aged 40 minutes and was used to ide and said developer contains about 0.005 to 1.5 process 10 square feet of films plus six sensitometric grams of said polyhedral haloborane per liter of develstrips. Results follow: oper.

' DEVELOPER WITHOUT POLYHEDRXL DEVELOPER wmr POLYHEDRAL aoRANE HALOBORANE senssitomletric Relative Speed Gamma Density at 5-! 1 Relative Speed Gamma Density at 5-11 amp e Fresh 5.00 3.72 440 390 400+ After 5 ft. 8.4 4.50 0.29 395 3.95 400+ After 10 to 2.3 4.80 0.03 as 4.00 2.52

At Step No. a of the {/2 wedge In addition, the developer without polyhedral halobo- SIThe process of claim 7 wher ein sz iid e rriulsion conrane went from a clear to a foamy, orange brown color tains about 0.01 to 1.3 grams of said polyethylene conwith a strong, bad odor while that with polyhedral densation product per 1.5 mole of silver halide and said haloborane had become only slightly brown and had no developer contains about 0.1 to 0.5 gram per liter of odor. One can easily see that the developer with polysaid polyhedral haloborane.

9. The process of claim 3 wherein said silver halide is silver chloride, silver bromide, silver chloro-bromide, silver bromo-iodide, silver chloro-iodide, mixtures of silver chloro-iodide-bromide or litho combinations.

10. The process of claim 3 wherein said polyethylene oxide condensation product is octylphenoxypolyethoxy ethanol and said polyhedral haloborane is H B Cl -7H O.

, l 1. In a developer for silver halide emulsions containing a polyethylene oxide condensation product, the improvement comprising the inclusion within said developer of a polyhedral haloborane, said polyhedral borane being a borane polyhedron, or fragments thereof, containing 10 to 12 boron atoms, and in which at least a majority of the hydrogen substituents have been replaced by halogen atoms.

12. The improvement of claim 1 1 wherein said developer contains, as the main developing agent, hydroquinone or substituted hydroquinones.

13. The improvement of claim 12 wherein said developer contains about 0.005 to 1.5 grams of said polyhedral borane per liter of developer.

14. The improvement of claim 13 wherein said developer contains about 0.1 to 0.5 grams of said polyhedral haloborane per liter of developer.

15. The process of claim 12 wherein said polyhedral haloborane is H B CI 7H O.

16. In a silver halide emulsion the improvement comprising the inclusion within said emulsion of a polyhedral haloborane and a polyethylene oxide condensation product.

17. The improvement of claim 16 wherein said emulsion forms a film on a support.

18. The improvement of claim 17 wherein said emulsion contains about 0.0025 to 2.0 grams of said polyethylene oxide condensation product per 1.5 moles of silver halide.

19. The improvement of claim 18 wherein said emulsion contains about 0.01 to 1.3 grams of said polyethylene oxide condensation product per 1.5 moles of silver halide. v

20. The improvement of claim 17 wherein said silver halide is silver chloride, silver bromide, silver chlorobromide, silver bromo-iodide, silver chloro-iodide, mixtures of silver chloro-iodide-bromide or litho combinations.

21. The improvement of claim 17 wherein said polyethylene oxide condensation product is octylphenoxypolyethoxy ethanol and said polyhedral haloborane is H2B12Cl 2'7H20. 

2. The process of claim 1 wherein said developer contains, as the main developing agent, hydroquinone or a substituted hydroquinone.
 3. The process of claim 2 in which said emulsion forms a layer on a support.
 4. The process of claim 3 wherein said polyhedral haloborane and said polyethylene oxide condensation product are present within said emulsion.
 5. The process of claim 4 wherein there is about 0.0025 to 2.0 grams of polyethylene oxide condensation product per 1.5 mole of silver halide in said emulsion.
 6. The process of claim 3 wherein said polyethylene oxide condensation product is present within said emulsion and said polyhedral haloborane is present within said developer.
 7. The process of claim 6 wherein said emulsion contains about 0.0025 to 2.0 grams of said polyethylene oxide condensation product per 1.5 moles of silver halide and said developer contains about 0.005 to 1.5 grams of said polyhedral haloborane per liter of developer.
 8. The process of claim 7 wherein said emulsion contains about 0.01 to 1.3 grams of said polyethylene condensation product per 1.5 mole of silver halide and said developer contains about 0.1 to 0.5 gram per liter of said polyhedral haloborane.
 9. The process of claim 3 wherein said silver halide is silver chloride, silver bromide, silver chloro-bromide, silver bromo-iodide, silver chloro-iodide, mixtures of silver chloro-iodide-bromide or litho combinations.
 10. The process of claim 3 wherein said polyethylene oxide condensation product is octylphenoxypolyethoxy ethanol and said polyhedral haloborane is H2B12Cl12.7H2O.
 11. In a developer for silver halide emulsions containing a polyethylene oxide condensation product, the improvement comprising the inclusion within said developer of a polyhedral haloborane, said polyhedral borane being a borane polyhedron, or fragments thereof, containing 10 to 12 boron atoms, and in which at least a majority of the hydrogen substituents have been replaced by halogen atoms.
 12. The improvement of claim 11 wherein said developer contains, as the main developing agent, hydroquinone or substituted hydroquinones.
 13. The improvement of claim 12 wherein said developer contains about 0.005 to 1.5 grams of said polyhedral borane per liter of developer.
 14. The improvement of claim 13 wherein said developer contains about 0.1 to 0.5 grams of said polyhedral haloborane per liter of developer.
 15. The process of claim 12 wherein said polyhedral haloborane is H2B12Cl12.7H2O.
 16. In a silver halide emulsion the improvement comprising the inclusion within said emulsion of a polyhedral haloborane and a polyethylene oxide condensation product.
 17. The improvement of claim 16 wherein said emulsion forms a film on a support.
 18. The improvement of claim 17 wherein said emulsion contains about 0.0025 to 2.0 grams of said polyethylene oxide condensation product per 1.5 moles of silver halide.
 19. The improvement of claim 18 wherein said emulsion contains about 0.01 to 1.3 grams of said polyethylene oxide condensation product per 1.5 moles of silver halide.
 20. The improvement of claim 17 wherein said silver halide is silver chloride, silver bromide, silver chloro-bromide, silver bromo-iodide, silver chloro-iodide, mixtures of silver chloro-iodide-bromide or litho combinations.
 21. The improvement of claim 17 wherein said polyethylene oxide condensation product is octylphenoxypolyethoxy ethanol and said polyhedral haloborane is H2B12Cl12.7H2O. 